The sacroiliac joint is a diarthrodial joint that joins the sacrum to the ilium bones of the pelvis. In the sacroiliac joint, the sacral surface has hyaline cartilage that moves against fibrocartilage of the iliac surface. The spinal column is configured so that the weight of the upper body rests on the sacroiliac joints at the juncture of the sacrum and ilia. Stress placed on the sacroiliac joints in an upright position of the body makes the lower back susceptible to injury.
Disorders of the sacroiliac joint can cause low back and radiating buttock and leg pain in patients suffering from degeneration and/or laxity of the sacroiliac joint. In some cases, the sacroiliac joint can undergo degeneration of the cartilaginous surfaces of the joint, similar to other articulating joints, which causes significant pain. The sacroiliac joint is also susceptible to trauma, with resulting degeneration, fracture or instability. It is estimated that disorders of the sacroiliac joint are a source of pain for millions of people suffering from back and radicular symptoms.
Non-surgical treatments, such as medication, injection, mobilization, rehabilitation and exercise can be effective. However, they may fail to permanently relieve the symptoms associated with these disorders. Surgical treatment of these disorders includes stabilization and/or arthrodesis. Stabilization can include the use of bone screws that are directly threaded across the joint. Arthrodesis may include immobilization of a joint and the removal of all of part of the cartilage from within the joint, permitting bone growth across the joint and resulting in a permanent fusion. The present disclosure describes an improvement over these prior art technologies.